U.S. patent application number 17/171991 was filed with the patent office on 2021-08-19 for grommet and wire harness.
The applicant listed for this patent is Yazaki Corporation. Invention is credited to Junya Kato, Masaru Kiuchi, Hirotaka Kiyota, Takeshi Onoda.
Application Number | 20210257133 17/171991 |
Document ID | / |
Family ID | 1000005445481 |
Filed Date | 2021-08-19 |
United States Patent
Application |
20210257133 |
Kind Code |
A1 |
Kiyota; Hirotaka ; et
al. |
August 19, 2021 |
GROMMET AND WIRE HARNESS
Abstract
A grommet includes a fitting body causing a circumferential edge
portion of a through hole provided in a wall body to be fitted into
a fitting groove provided in an outer wall, and a first cylinder
and a second cylinder causing a harness body to be extracted
through the cylinder. The fitting body includes a cylindrical
portion, a plurality of ribs rising from an outer circumferential
wall surface of the cylindrical portion and disposed on the outer
circumferential wall surface at equal intervals in a
circumferential direction, and a first support portion and a second
support portion provided for each of the ribs. The first support
portion and the second support portion project from the outer
circumferential wall surface to be high enough to suppress elastic
deformation of the rib in the circumferential direction toward the
outer circumferential wall surface.
Inventors: |
Kiyota; Hirotaka; (Shizuoka,
JP) ; Kiuchi; Masaru; (Shizuoka, JP) ; Onoda;
Takeshi; (Shizuoka, JP) ; Kato; Junya;
(Shizuoka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Yazaki Corporation |
Tokyo |
|
JP |
|
|
Family ID: |
1000005445481 |
Appl. No.: |
17/171991 |
Filed: |
February 9, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16L 5/00 20130101; H01B
17/586 20130101 |
International
Class: |
H01B 17/58 20060101
H01B017/58; F16L 5/00 20060101 F16L005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 17, 2020 |
JP |
2020-024487 |
Claims
1. A grommet comprising: a fitting body causing a circumferential
edge portion of a through hole having a circular shape and provided
in a wall body to be fitted into a fitting groove having an annular
shape and provided in an outer wall, and causing a harness body,
routed along a hole axis of the through hole in a space in the
outer wall to be extracted from the space through a first draw-out
aperture having a circular shape and disposed at a first axial end
and a second draw-out aperture having a circular shape and disposed
at a second axial end; a first cylinder having a cylinder axis
coaxial with an axis of the fitting body, projecting outward from a
circumferential edge portion of the first draw-out aperture, and
causing the harness body in the space to be extracted through
inside of the first cylinder; and a second cylinder having a
cylinder axis coaxial with the axis of the fitting body, projecting
outward from a circumferential edge portion of the second draw-out
aperture, and causing the harness body in the space to be extracted
through inside of the second cylinder, wherein the fitting body
includes a cylindrical portion having an outer circumferential wall
surface joined to the fitting groove at a position closer to the
first cylinder than the fitting groove in the outer wall, and
gradually reduced in diameter as being away coaxially from the
fitting groove, a plurality of ribs rising from the outer
circumferential wall surface of the cylindrical portion and
disposed on the outer circumferential wall surface at equal
intervals in a circumferential direction, and each extending on the
outer circumferential wall surface at least from a position equal
in diameter to the circumferential edge portion of the through hole
to a radially outer end, a first support portion provided for each
of the ribs and supporting a side, adjacent to the outer
circumferential wall surface, of a first side wall of the rib on a
first side in the circumferential direction, and a second support
portion provided for each of the ribs and supporting a side,
adjacent to the outer circumferential wall surface, of a second
side wall of the rib on a second side in the circumferential
direction, the rib is shaped to enable elastic deformation in the
circumferential direction, and the first support portion and the
second support portion project from the outer circumferential wall
surface to be high enough to suppress elastic deformation of the
rib in the circumferential direction toward the outer
circumferential wall surface.
2. The grommet according to claim 1, wherein the rib is shaped to
enable inclining deformation in the circumferential direction
within an elastic region, and the first support portion and the
second support portion project from the outer circumferential wall
surface to be high enough to suppress at least inclining
deformation of the rib in the circumferential direction toward the
outer circumferential wall surface.
3. The grommet according to claim 1, wherein the first support
portion projects to the first side in the circumferential direction
from the side, adjacent to the outer circumferential wall surface,
of the first side wall, and the second support portion projects to
the second side in the circumferential direction from the side,
adjacent to the outer circumferential wall surface, of the second
side wall.
4. The grommet according to claim 2, wherein the first support
portion projects to the first side in the circumferential direction
from the side, adjacent to the outer circumferential wall surface,
of the first side wall, and the second support portion projects to
the second side in the circumferential direction from the side,
adjacent to the outer circumferential wall surface, of the second
side wall.
5. The grommet according to claim I, wherein the fitting body
includes a locked portion that is disposed radially inside the
ribs, rises from the outer circumferential wall surface for each of
the ribs, is configured to be locked to an outer circumferential
surface of the first cylinder when the first cylinder is shifted
relatively to the fitting body along the cylinder axis toward the
second cylinder, to suppress elastic deformation of the cylindrical
portion or reduce elastic deformation.
6. The grommet according to claim 2, wherein the fitting body
includes a locked portion that is disposed radially inside the
ribs, rises from the outer circumferential wall surface for each of
the ribs, is configured to be locked to an outer circumferential
surface of the first cylinder when the first cylinder is shifted
relatively to the fitting body along the cylinder axis toward the
second cylinder, to suppress elastic deformation of the cylindrical
portion or reduce elastic deformation.
7. The grommet according to claim 3, wherein the fitting body
includes a locked portion that is disposed radially inside the
ribs, rises from the outer circumferential wall surface for each of
the ribs, is configured to be locked to as outer circumferential
surface of the first cylinder when the first cylinder is shifted
relatively to the fitting body along the cylinder axis toward the
second cylinder, to suppress elastic deformation of the cylindrical
portion or reduce elastic deformation.
8. The grommet according to claim 4, wherein the fitting body
includes a locked portion that is disposed radially inside the
ribs, rises from the outer circumferential wall surface for each of
the ribs, is configured to be locked to as outer circumferential
surface of the first cylinder when the first cylinder is shifted
relatively to the fitting body along the cylinder axis toward the
second cylinder, to suppress elastic deformation of the cylindrical
portion or reduce elastic deformation.
9. A wire harness comprising: a harness body; and a grommet
protecting the harness body, wherein the grommet including: a
fitting body causing a circumferential edge portion of a through
hole having a circular shape and provided in a wall body to be
fitted into a fitting groove having an annular shape and provided
in an outer wall, and causing the harness body routed along a hole
axis of the through hole in a space in the outer wall to be
extracted from the space through a first draw-out aperture having a
circular shape and disposed at a first axial end and a second
draw-out aperture having a circular shape and disposed at a second
axial end; a first cylinder having a cylinder axis coaxial with an
axis of the fitting body, projecting outward from a circumferential
edge portion of the first draw-out aperture, and causing the
harness body in the space to be extracted through inside of the
first cylinder; and a second cylinder having a cylinder axis
coaxial with the axis of the fitting body, projecting outward from
a circumferential edge portion of the second draw-out aperture, and
causing the harness body in the space to be extracted through
inside of the second cylinder, wherein the fitting body includes a
cylindrical portion having an outer circumferential wall surface
joined to the fitting groove at a position closer to the first
cylinder than the fitting groove in the outer wall, and gradually
reduced in diameter as being away coaxially from the fitting
groove, a plurality of ribs rising from the outer circumferential
wall surface of the cylindrical portion and disposed on the outer
circumferential wall surface at equal intervals in a
circumferential direction, and each extending on the outer
circumferential wall surface at least from a positon equal in
diameter to the circumferential edge portion of the through hole to
a radially outer end, a first support portion provided for each of
the ribs and supporting a side, adjacent to the outer
circumferential wall surface, of a first side wall of the rib on a
first side in the circumferential direction, and a second support
portion provided for each of the ribs and supporting a side,
adjacent to the outer circumferential wall surface, of a second
side wall of the rib on a second side in the circumferential
direction, the rib is shaped to enable elastic deformation in the
circumferential direction, and the first support portion and the
second support portion project from the outer circumferential wall
surface to be high enough to suppress elastic deformation of the
rib in the circumferential direction toward the outer
circumferential wall surface.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] The present application claims priority to and incorporates
by reference the entire contents of Japanese Patent Application No.
2020-024487 filed in Japan on Feb. 17, 2020.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The present invention relates to a grommet and a wire
harness.
2. Description of the Related Art
[0003] A wire harness is conventionally provided with an electric
wire penetrating a circular through bole is a wall body (e.g. a
vehicle body panel of a vehicle) to route the electric wire in both
spaces partitioned by the wall body. The wall body is accordingly
provided with a grommet closing a gap between the through hole and
the electric wire for protection of the electric wire from a
circumferential edge portion of the through hole as well as
prevention of liquid entry to the gap. The grommet exemplarily
includes a fitting body configured to fit the circumferential edge
portion of the through hole into an annular fitting groove and
route the electric wire in the fitting body along a hole axis of
the through hole, a first cylinder having a cylindrical shape,
projecting from a first axial end of The fitting body, and
extracting the electric wire in the fitting body through the
cylinder, and a second cylinder having a cylindrical shape,
projecting from a second axial end of the fitting body, and
extracting the electric wire in the fitting body through the
cylinder. In the grommet, one of the cylinders is pulled along a
cylinder axis, the fitting body caught by the circumferential edge
portion of the through hole being deformed and sliding guides the
circumferential edge portion to be fitted into the fitting groove.
Such a grommet of this type is disclosed in Japanese Patent
Application Laid-open No. 2005-190973 and the like. In order for
decrease in insertion force for assembly of the fitting body to the
through hole in the wall body, the grommet according to Japanese
Patent Application Laid-open No. 2005-190973 provides a plurality
of ribs rising at equal intervals on a surface of the fitting body
along an entire circumference and thus achieves reduction in
frictional resistance upon sliding. Each of the ribs is in contact
with the circumferential edge portion of the through hole until
guided into the fitting groove, for reduction in contact area
between the circumferential edge portion of the through hole and
the fitting body being sliding.
[0004] A wire harness needs to enable further reduction in force of
inserting the fitting body to the through hole in the wall body,
for improvement in assembling workability. Meanwhile, a grommet
needs to keep an assembled state after being assembled to the
through hole is the wall body.
SUMMARY OF THE INVENTION
[0005] In view of these, it is an object of the present invention
to provide a grommet and a wire harness that can reduce insertion
force as well as can keep an assembled state.
[0006] In order to achieve the above mentioned object, a grommet
according to one aspect of the present invention includes a fitting
body causing a circumferential edge portion of a through hole
having a circular shape and provided in a wall body to be fitted
into a fitting groove having an annular shape and provided in an
outer wall, and causing a harness body routed along a hole axis of
the through hole in a space in the outer wall to be extracted from
the space through a first draw-out aperture having a circular shape
and disposed at a first axial end and a second draw-out aperture
having a circular shape and disposed at a second axial end; a first
cylinder having a cylinder axis coaxial with an axis of the fitting
body, projecting outward from a circumferential edge portion of the
first draw-out aperture, and causing the harness body in the space
to be extracted through inside of the first cylinder; and a second
cylinder having a cylinder axis coaxial with the axis of The
fitting body, projecting outward from a circumferential edge
portion of the second draw-out aperture, and causing the harness
body in the space to be extracted through inside of the second
cylinder, wherein the fitting body includes a cylindrical portion
having an outer circumferential wall surface joined to the fitting
groove at a position closer to the first cylinder than the fitting
groove in the outer wall, and gradually reduced in diameter as
being away coaxially from the fitting groove, a plurality of ribs
rising from the outer circumferential wall surface of the
cylindrical portion and disposed on the outer circumferential wall
surface at equal intervals in a circumferential direction, and each
extending on the outer circumferential wall surface at least from a
position equal in diameter to the circumferential edge portion of
the through hole to a radially outer end, a first support portion
provided for each of the ribs and supporting a side, adjacent to
the outer circumferential wall surface, of a first side wall of The
rib on a first side in the circumferential direction, and a second
support portion provided for each of the ribs and supporting a
side, adjacent to the outer circumferential wall surface, of a
second side wall of the rib on a second side in the circumferential
direction, the rib is shaped to enable elastic deformation in the
circumferential direction, and the first support portion and the
second support portion project from the outer circumferential wall
surface to be high enough to suppress elastic deformation of the
rib in the circumferential direction toward the outer
circumferential wall surface.
[0007] According to another aspect of the present invention, in the
grommet, it is possible to configure that the rib is shaped to
enable inclining deformation in the circumferential direction
within an elastic region, and the first support portion and the
second support portion. project from the outer circumferential wall
surface to be high enough to suppress at least inclining
deformation of the rib in the circumferential direction toward the
outer circumferential wall surface.
[0008] According to still another aspect of the present invention,
in the grommet, it is possible to configure that the first support
portion projects to the first side in the circumferential direction
from the side, adjacent to the outer circumferential wall surface,
of the first side wall, and the second support portion projects to
the second side in the circumferential direction from the side,
adjacent to the outer circumferential wall surface, of the second
side wall.
[0009] According to still another aspect of the present. invention,
in the grommet, it is possible to configure that the fitting body
includes a locked portion that is disposed radially inside the
ribs, rises from the outer circumferential wall surface for each of
the ribs, is configured to be locked to an outer circumferential
surface of the first cylinder when the first cylinder is shifted
relatively to the fitting body along the cylinder axis toward the
second cylinder, to suppress elastic deformation of the cylindrical
portion or reduce elastic deformation.
[0010] In order to achieve the above mentioned object, a wire
harness according to still anther aspect of the present invention
includes a harness body; and a grommet protecting the harness body,
wherein the grommet including: a fitting body causing a
circumferential edge portion of a through hole having a circular
shape and provided in a wall body to be fitted into a fitting
groove having an annular shape and provided in an outer wall, and
causing the harness body routed along a hole axis of the through
hole in a space in the outer wall to be extracted from the space
through a first draw-out aperture having a circular shape and
disposed at a first axial end and a second draw-out aperture having
a circular shape and disposed at a second axial end; a first
cylinder having a cylinder axis coaxial with an axis of the fitting
body, projecting outward from a circumferential edge portion of the
first draw-cut aperture, and causing the harness body in the space
to be extracted through inside of the first cylinder; and a second
cylinder having a cylinder axis coaxial with the axis of the
fitting body, projecting outward from a circumferential edge
portion of the second draw-out aperture, and causing the harness
body in the space to be extracted through inside of the second
cylinder, wherein the fitting body includes a cylindrical portion
having an outer circumferential wall surface joined to the fitting
groove at a position closer to the first cylinder than the fitting
groove in the outer wall, and gradually reduced in diameter as
being away coaxially from the fitting groove, a plurality of ribs
rising from the outer circumferential wall surface of the
cylindrical portion and disposed on the outer circumferential wall
surface at equal intervals in a circumferential direction, and each
extending on the outer circumferential wall surface at least from a
position equal in diameter to the circumferential edge portion of
the through hole to a radially outer end, a first support portion
provided for each of the ribs and supporting a side, adjacent to
the outer circumferential wall surface, of a first side wall of the
rib on a first side in the circumferential direction, and a second
support portion provided for each of the ribs and supporting a
side, adjacent to the outer circumferential wall surface, of a
second side wall of the rib on a second side in the circumferential
direction, the rib is shaped to enable elastic deformation in the
circumferential direction, and the first support portion and the
second support portion project from the outer circumferential wall
surface to be high enough to suppress elastic deformation of the
rib in the circumferential direction toward the outer
circumferential wall surface.
[0011] The above and other objects, features, advantages and
technical and industrial significance of this invention will be
better understood by reading the following detailed description of
presently preferred embodiments of the invention, when considered
in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a perspective view of a grommet and a wire harness
according to an embodiment;
[0013] FIG. 2 is a plan view of the grommet in an axial
direction;
[0014] FIG. 3 is a plan view of the grommet in a direction
perpendicular to the axial direction;
[0015] FIG. 4 is a sectional view taken along line X-X indicated in
FIG. 2;
[0016] FIG. 5 is a partial enlarged sectional view taken along line
Y-Y indicated in FIG. 3; and
[0017] FIG. 6 is a perspective view of the grommet for illustration
of a rib.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] A grommet and a wire harness according to an embodiment of
the present invention will hereinafter be described in detail with
reference to the drawings. This invention is not to be limited by
the embodiment.
Embodiment
[0019] A grommet and a wire harness according to as embodiment of
the present invention will be described with reference to FIG. 1 to
FIG. 6.
[0020] FIG. 1 to FIG. 5 include reference sign 1 denoting a grommet
according to the present embodiment. The grommet 1 protects a
harness body We inserted through a circular through hole Pw1
provided in a wall body Pw. The harness body We includes a single
or a plurality of bundled electric wires functioning as
communication lines or power supply lines. When the harness body We
includes the plurality of electric wires, the plurality of electric
wires is collected together by an exterior component such as a
corrugate tube or a resin tape. Examples of the wall body Pw for a
vehicle includes a vehicle body panel. The harness body We is
inserted through the through hole Pw1 in the wall body Pw so as to
be routed in two spaces (e.g. an engine compartment and a cabin)
partitioned by the wall body Pw. The harness body We is used for
communication between devices in these spaces, power supply from a
power source in a first one of the spaces to an electric device in
a second one of the spaces, and the like. The grommet 1 is attached
to the wall body Pw so as to protect the harness body We from a
circumferential edge portion of the through hole Pw1 in the wall
body Pw and prevent liquid (e.g. water) from entering a gap between
the through hole Pw1 and the harness body We. Herein, the grommet 1
and the harness body We assembled together will be referred to as a
wire harness WH (FIG. 1).
[0021] The grommet 1 is made of an elastic material such as an
elastomer. The grommet 1 integrally includes a fitting body 10, a
first cylinder 20A, and a second cylinder 20B to be described
below. In the grommet 1, the fitting body 10 has a first axial end
coupled coaxially to the first cylinder 20A, and a second axial end
coupled coaxially to the second cylinder 20B.
[0022] The grommet 1 includes the fitting body 10 fitted to the
circumferential edge portion of the through hole Pw1 (FIG. 1 to
FIG. 4). The fitting body 10 is constituted by an outer wall 12
having an interior serving as a space 11 (FIG. 4). The outer wall
12 has a gradually changing cylindrical portion (hereinafter,
referred to as a "first cylindrical portion") 12A having a
gradually reducing diameter along a cylinder axis toward the first
cylinder 20A, and a gradually changing cylindrical portion
(hereinafter, referred to as a "second cylindrical portion") 12B
having a gradually reducing diameter along a cylinder axis toward
the second cylinder 20B. The outer wall 12 exemplified herein is
shaped to include the first cylindrical portion 12A having a
truncated cone shape and the second cylindrical portion 12B having
a truncated cone shape combined coaxally with each other. In this
outer wall 12, the first cylindrical portion 12A and the second
cylindrical portion 12B have bottoms equal in diameter and coupled
coaxially to each other, and tops disposed at respective axial
ends. In the grommet 1, the first cylinder 20A is coupled to the
top of the first cylindrical portion 12A, and the second cylinder
20B is coupled to the top of the second cylindrical portion
12B.
[0023] The outer wall 12 has an outer circumferential wall surface
12a provided coaxially with an annular fitting groove 13 receiving
the circumferential edge portion of the through hole Pw1 in the
wall body Pw (FIG. 1, FIG. 3, and FIG. 4). The fitting groove 13 is
provided at the coupled bottoms of the first cylindrical portion
12A and the second cylindrical portion 12B, or adjacent to the
bottom of one of the first cylindrical portion 12A and the second
cylindrical portion 12B. The fitting body 10 exemplified herein has
the fitting groove 13 provided at the coupled bottoms of the first
cylindrical portion 12A and the second cylindrical portion 12B. The
first cylindrical portion 12A has the outer circumferential wall
surface 12a joined to the fitting groove 13 at a position closer to
the first cylinder 20A than the fitting groove 13 in the outer wall
12, and has a gradually changing cylindrical shape with the
gradually reduced diameter as being away coaxially from the fitting
groove 13. The second cylindrical portion 12B has the outer
circumferential wail surface 12a joined to the fitting groove 13 at
a position closer to the second cylinder 20B than the fitting
groove 13 in the outer wall 12, and has a gradually changing
cylindrical shape with the gradually reduced diameter as being away
coaxially from the fitting groove 13.
[0024] The space 11 in the outer wall 12 accommodates the harness
body We routed along a hole axis of the through hole Pw1. The
fitting body 10 causes the harness body We to be extracted from the
space 11 through a first draw-out aperture 14A (FIG. 4) at the
first axial end and a second draw-out aperture 14B (FIG. 4) at the
second axial end. The tops of the first cylindrical portion 12A and
the second cylindrical portion 123 are opened in the outer wall 12.
In the outer wall 12, the first draw-out aperture 14A is
constituted by a circular opening provided in the top of the first
cylindrical portion 12A, and the second draw-out aperture 14B is
constituted by a circular opening provided in the top of the second
cylindrical portion 12B.
[0025] Furthermore, the grommet 1 includes the first cylinder 20A
having the cylinder axis coaxial with an axis of the fitting body
10, projecting outward from a circumferential edge portion of the
first draw-out aperture 14A, and causing the harness body We in the
space 11 to be extracted through the cylinder, and the second
cylinder 20B having the cylinder axis coaxially with the axis of
the fitting body 10, projecting outward from a circumferential edge
portion of the second draw-out aperture 14B, and causing the
harness body We in the space 11 to be extracted through the
cylinder (FIG. 1, FIG. 3, and FIG. 4). The first cylinder 20A has a
cantilever shape with a fixed end adjacent to the first draw-out
aperture 14A and a free end projecting along the cylinder axis. The
second cylinder 20B has a cantilever shape with a fixed end
adjacent to the second draw-out aperture 14B and a free end
projecting along the cylinder axis.
[0026] The grommet 1 assembled to the harness body We is inserted,
from the free end of the first cylinder 20A, to the through hole
Pw1 in the wall body Pw. In the grommet 1, the first cylinder 20A
is pulled along the cylinder axis to elastically deform the fitting
body 10 caught by the circumferential edge portion of the through
hole Pw1 in the wall body Pw as well as guide the circumferential
edge portion to fit the circumferential edge portion into the
fitting groove 13. The grommet 1 thus has frictional resistance due
to sliding generated between the fitting body 10 and the
circumferential edge portion of the through hole Pw1 in the wall
body Pw. As the frictional resistance is larger, the fitting body
10 needs to be assembled to the through hole Pw1 in the wall body
Pw with larger insertion force (force of pulling the first cylinder
20A).
[0027] In view of this, the grommet 1 according to the present
embodiment includes ribs 15 provided at the fitting body 10 for
reduction in frictional resistance (FIG. 1 to FIG. 5).
[0028] The ribs 15 have a plural number, rise from the outer
circumferential wall surface 12a of the first cylindrical portion
12A to be disposed at equal intervals in a circumferential
direction, and each extend at least from a position equal in
diameter to the circumferential edge portion of the through hole
Pw1 in the wall body Pw in the outer circumferential wall surface
12a to a radially outer end. The ribs 15 each include a rising end
surface 15a (FIG. 2 to FIG. 5) that comes into come into contact
with the circumferential edge portion of the through hole Pw1 in
the wall body Pw when the first cylinder 20A inserted to the
through hole Pw1 in the wall body Pw is pulled along the cylinder
axis. When the fitting body 10 in the grommet 1 assembled to the
through hole Pw1 in the wall body Pw, the plurality of ribs 15
comes into contact with the circumferential edge portion of the
through hole Pw1 in the wall body Pw as well as slides, to achieve
reduction in contact area with the circumferential edge portion for
smaller frictional resistance and reduced insertion force to the
through hole Pw1 in the wall body Pw, in comparison to a case where
The outer circumferential wall surface 12a of the first cylindrical
portion 12A comes into contact with the circumferential edge
portion of the through hole Pw1 in the wall body Pw as well as
slides.
[0029] The ribs 15 are shaped to be elastically deformable in the
circumferential direction (along each of the ribs 15 being
arrayed). Such elastic deformation in the circumferential direction
indicates circumferential deformation within an elastic region of
each of the ribs 15 when the rising end surface 15a receives force
along the cylinder axis. The ribs 15 are formed to have
circumferential width (in other words, small width) enabling
elastic deformation in the circumferential direction with force
applied along the cylinder axis to the end surface 15a. In the
grommet 1, the plurality of ribs 15 having such small width enables
reduction in contact area with the circumferential edge portion of
the through hole Pw1 in the wall body Pw, reduction in frictional
resistance, and reduction in insertion force to the through hole
Pw1 in the wall body Pw.
[0030] Specifically, the ribs 15 are shaped to enable inclining
deformation in the circumferential direction within The elastic
region (FIG. 6). In other words, the ribs 15 are each formed to
have small circumferential width so as to enable inclining
deformation in the circumferential direction (e.g. bending at a
route adjacent to the outer circumferential wall surface 12a, or
bending at a position between the route and the end surface 15a)
within the elastic region with force along the cylinder axis
applied to the rising end surface 15a. The ribs 15 small in width
may be compressed within the elastic region by the circumferential
edge portion or may be pressed by the circumferential edge portion
to have inclining deformation in the circumferential direction
within the elastic region when the rising end surface 15a receives
force along the cylinder axis from the circumferential edge portion
of the through hole Pw1 in the wall body Pw. Each of the ribs 15
may thus be increased in contact area with the circumferential edge
portion in comparison to a case where the rising end surface 15a
and the circumferential edge portion of the through hole Pw1 in the
wall body Pw are in contact with each other. Accordingly, the ribs
15 small in width do not contribute to rigidity improvement of the
first cylindrical portion 12A. Specifically, the ribs 15 do not
effectively suppress elastic deformation of the fitting body 10
having been assembled to the through hole Pw1 in the wall body
Pw.
[0031] In view of this, the fitting body 10 in the grommet 1
according to the present embodiment is provided with a first
support portion 16A and a second support portion 16B for
sufficiently effective reduction in insertion force by each of the
ribs 15 as well as effective suppression of elastic deformation or
effective reduction in elastic deformation of the fitting body 10
having been assembled (FIG. 1 to FIG. 5). The first support portion
16A and the second support portion 16B are provided to each of the
ribs 15.
[0032] The first support portion 16A supports a side, adjacent to
the outer circumferential wall surface 12a, of a first side wall
15b on a first side in the circumferential direction of the rib 15,
and projects from The outer circumferential wall surface 12a to be
high enough to suppress elastic deformation of the rib 15 in the
circumferential direction toward the outer circumferential wall
surface 12a (FIG. 2 and FIG. 5). Specifically, the first support
portion 16A projects from the outer circumferential wall surface
12a to be high enough to suppress at least inclining deformation of
the rib 15 in the circumferential direction toward the outer
circumferential wall surface 12a. The first support portion 16A
projects to the first side in the circumferential direction also
from the side, adjacent to the outer circumferential wall surface
12a, of the first side wall 15b, and is provided integrally with
the rib 15. The first support portion 16A further projects to the
first side in the circumferential direction as the first
cylindrical portion 12A has a larger rigidity improvement margin.
The first support portion 16A exemplified herein has a cubic shape
extending at least from the position equal in diameter to the
circumferential edge portion of the through hole Pw1 in the wall
body Pw in the outer circumferential wall surface 12a to the
radially outer end and projecting to the first side in the
circumferential direction from the side, adjacent to the outer
circumferential wall surface 12a, of the first side wall 15b.
[0033] The second support portion 16B supports a side, adjacent to
the outer circumferential wall surface 12a, of a second side wall
15c on a second side in the circumferential direction of the rib
15, and projects from the outer circumferential wall surface 12a to
be high enough to suppress elastic deformation of the rib 15 in the
circumferential direction toward the outer circumferential wall
surface 12a (FIG. 2 and FIG. 5). Specifically, the second support
portion 16B projects from the outer circumferential wall surface
12a to be high enough to suppress at least inclining deformation of
the rib 15 in the circumferential direction toward the outer
circumferential wall surface 12a. The second support portion 16B
projects to the second side in the circumferential direction also
from the side, adjacent to the outer circumferential wall surface
12a, of the second side wall 15c, and is provided integrally with
the rib 15. The second support portion 16B further projects to the
second side in the circumferential direction as the first
cylindrical portion 12A has a larger rigidity improvement margin.
The second support portion 16B exemplified herein has a cubic shape
extending at least from the position equal in diameter to the
circumferential edge portion of the through hole Pw1 in the wall
body Pw in the outer circumferential wall surface 12a to the
radially outer end and projecting to the second side in the
circumferential direction from the side, adjacent to the outer
circumferential wall surface 12a, of the second side wall 15c.
[0034] In the grommet 1, the first cylindrical portion 12A of the
fitting body 10 is provided with the ribs 15 each having the small
width at the rising end surface 15a as described above, and the
first cylindrical portion 12A is provided with the first support
portion 16A and the second support portion 16B supporting the
sides, adjacent to an outer circumferential wall surface 12a, of
the first side wall 15b and the second side wall 15c of the rib 15
to prevent elastic deformation in the circumferential direction.
The first cylindrical portion 12A accordingly has suppressed
bending deformation within the elastic region or reduction in
bending deformation at positions of the first support portion 16A
and the second support portion 16B, for rigidity improvement at a
radially outer portion. The fitting body 10 having been assembled
to the through hole Pw1 in the wall body Pw is thus suppressed from
elastic deformation or reduced in elastic deformation at the
radially outer portion of the first cylindrical portion 12A. In the
grommet 1, the fitting groove 13 is provided at the radially outer
portion of the fitting body 10. Due to effective suppression of
elastic deformation at the radially outer portion of the first
cylindrical portion 12A or the like, the circumferential edge
portion of the through hole Pw1 in the wall body Pw can be kept
fitted in the fitting groove 13 and the fitting body 10 can keep
the assembled state to the through hole Pw1.
[0035] In the rib 15 integrally provided with the first support
portion 16A and the second support portion 16B, the rising end
surface 15a of the rib 15 projects from projecting end surfaces 16a
and 16a of the first support portion 16A and the second support
portion 16B from the outer circumferential wall surface 12a (FIG. 3
and FIG. 5). The first support portion 16A and the second support
portion 16B are higher than the outer circumferential wall surface
12a so as to allow elastic deformation in the circumferential
direction of a projecting portion of the rib 15 from the end
surfaces 16a and 16a when the rising end surface 15a receives force
along the cylinder axis. Examples of such elastic deformation in
the circumferential direction of the projecting portion of the rib
15 include inclining deformation in the circumferential direction
within the elastic region when the rising end surface 15a receives
force along the cylinder axis, and deformation like shear
deformation of circumferential displacement from the end surface
15a within the elastic region when force along the cylinder axis is
applied. The projecting portion of the rib 15 is exemplarily shaped
to satisfy "1/2.ltoreq.W/H.ltoreq.1" as a relation between
projecting height H from each of the end surfaces 16a and 16a and
circumferential width W. The projecting portion of the rib 15 is
alternatively shaped such that the projecting height H from each of
the end surfaces 16a and 16a is equal to or more than 1 mm.
[0036] When the rising end surface 15a receives force along the
cylinder axis from the circumferential edge portion of the through
hole Pw1 in the wall body Pw, the projecting portion of the rib 15
can slide with the end surface 15a kept in contact with the
circumferential edge portion. The grommet 1 can thus continuously
achieve suppression in contact area between each of the ribs 15 and
the circumferential edge portion of the through hole Pw1 in the
wall body Pw and can keep small frictional resistance therebetween
when the fitting body 10 is assembled to the through hole Pw1 in
the wall body Pw, for reduction in insertion force to the through
hole Pw1 in the wall body Pw.
[0037] The first support portion 16A and the second support portion
16B exemplified herein project from the outer circumferential wall
surface 12a to be high enough to prevent inclining deformation of
the rib 15 in the circumferential direction. The first support
portion 16A and the second support portion 16B are herein shaped
similarly to each other. The projecting portion of the rib 15
exemplified herein may have deformation like shear deformation in
the circumferential direction within the elastic region or
compressive deformation within the elastic region when the rising
end surface 15a receives force along the cylinder axis. When the
rising end surface 15a receives force along the cylinder axis from
the circumferential edge portion of the through hole Pw1 in the
wall body Pw, the projecting portion of the rib 15 exemplified
herein can slide with the end surface 15a kept in contact with the
circumferential edge portion while having shear deformation or
compressive deformation caused by the circumferential edge portion.
The grommet 1 exemplified herein can thus achieve reduction in
insertion force to the through hole Pw1 in the wall body Pw when
the fitting body 10 is assembled to the through hole Pw1 in the
wall body Pw.
[0038] In the rib 15 integrally provide d with the first support
portion 16A and the second support portion 16B, the side adjacent
to the outer circumferential wall surface 12a of the rib 15, the
first support portion 16A, and the second support portion 16B are
collectively provided as a rigidity improving portion projecting
from the outer circumferential wall surface 12a. The first
cylindrical portion 12A has suppressed bending deformation within
the elastic region or reduction in bending deformation at a
position of the rigidity improving portion. The first cylindrical
portion 12A accordingly has a plurality of rigidity improving
portions disposed at equal intervals in the circumferential
direction, for further rigidity improvement at the radially outer
portion provided with the ribs 15 and the like. With the plurality
of rigidity improving portions provided at the first cylindrical
portion 12A, the fitting body 10 having been assembled to the
through hole Pw1 in the wall body Pw can achieve more effective
suppression of elastic deformation or further reduction in elastic
deformation at the radially outer portion of the first cylindrical
portion 12A. In the grommet 1, the circumferential edge portion of
the through hole Pw1 in the wall body Pw can thus be easily kept
fitted in the fitting groove 13 and the fitting body 10 can keep
the assembled state to the through hole Pw1.
[0039] As described above, the grommet 1 and the wire harness WH
according to the present embodiment can reduce insertion force to
the through hole Pw1 in the wall body Pw as well as can keep the
assembled state to the through hole Pw1.
[0040] The fitting body 10 in the grommet 1 includes a locked
portion 17 that is disposed radially inside the ribs 15, rises from
the outer circumferential wall surface 12a for each of the ribs 15,
and is configured to be locked to an outer circumferential surface
20a of the first cylinder 20A when the first cylinder 20A is
shifted relatively to the fitting body 10 along the cylinder axis
toward the second cylinder 20B, for suppression of elastic
deformation of the first cylindrical portion 12A or reduction in
elastic deformation (FIG. 1 to FIG. 5). The locked portion 17
rotates along arrow A indicated in FIG. 4 to be locked to the outer
circumferential surface 20a of the first cylinder 20A when the
first cylinder 20A is shifted relatively to the fitting body 10
along the cylinder axis toward the second cylinder 20B. The locked
portion 17 exemplified herein has a cubic shape projecting from the
outer circumferential wall surface 12a and provided integrally with
the rib 15, the first support portion 16A, and the second support
portion 16B.
[0041] In the grommet 1 and the wire harness WH according to the
present embodiment, the locked portions 17 improve rigidity at a
radially inner portion of the first cylindrical portion 12A, for
suppression of elastic deformation or reduction in elastic
deformation at the radially inner portion of the first cylindrical
portion 12A in the fitting body 10 having been assembled to the
through hole Pw1 in the wall body Pw. In the grommet 1 and the wire
harness WH, due to also effective suppression of elastic
deformation at the radially inner portion of the first cylindrical
portion 12A and the like, the circumferential edge portion of the
through hole Pw1 in the wall body Pw can be kept fitted in the
fitting groove 13 and the fitting body 10 can keep the assembled
state to the through hole Pw1.
[0042] In the grommet and the wire harness according to the present
embodiment, the ribs are each formed to have circumferential width
(in other words, small width) enabling elastic deformation in the
circumferential direction due to force applied along the cylinder
axis to a rising end surface. In the grommet and the wire harness,
the plurality of ribs having such small width enables reduction in
contact area with the circumferential edge portion of the through
hole in the wall body, reduction in frictional resistance, and
reduction in insertion force to the through hole in the wall body.
In the grommet and the wire harness according to the present
embodiment, the fitting body includes a first cylindrical portion
provided with the ribs having the small width at the rising end
surface as described above, and the first cylindrical portion is
provided with the first support portion and the second support
portion supporting the sides, adjacent to an outer circumferential
wall surface, of the first side wall and the second side wall of
the rib, to prevent elastic deformation in the circumferential
direction. The first cylindrical portion accordingly has suppressed
bending deformation within the elastic region or reduction in
bending deformation at positions of the first support portion and
the second support portion, for rigidity improvement at a radially
outer portion. The fitting body having been assembled to the
through hole in the wall body is thus suppressed from elastic
deformation or reduced in elastic deformation at the radially outer
portion of the first cylindrical portion. In the grommet and the
wire harness, the fitting groove is provided at the radially outer
portion of the fitting body. Due to effective suppression of
elastic deformation at the radially outer portion of the first
cylindrical portion or the like, the circumferential edge portion
of the through hole in the wall body can be kept fitted in the
fitting groove and the fitting body can keep the assembled state to
the through hole. As described above, the grommet and the wire
harness according to the present invention can reduce insertion
force to the through hole in the wall body as well as can keep the
assembled state to the through hole.
[0043] Although the invention has been described with respect to
specific embodiments for a complete and clear disclosure, the
appended claims are not to be thus limited but are to be construed
as embodying all modifications and alternative constructions that
may occur to one skilled in the art that fairly fail within the
basic teaching herein set forth.
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